Glaucoma is a disease of the eye that affects millions of people. Glaucoma is associated with an increase in intraocular pressure resulting either from a failure of a drainage system of an eye to adequately remove aqueous humor from an anterior chamber of the eye or overproduction of aqueous humor by a ciliary body in the eye. Build-up of aqueous humor and resulting intraocular pressure may result in irreversible damage to the optic nerve and the retina, which may lead to irreversible retinal damage and blindness.
Glaucoma may be treated by surgical intervention that involves placing a shunt in the eye to result in production of fluid flow pathways between the anterior chamber and various structures of the eye involved in aqueous humor drainage (e.g., Schlemm's canal, the sclera, or the subconjunctival space). Such fluid flow pathways allow for aqueous humor to exit the anterior chamber. Generally, the surgical intervention to implant the shunt involves inserting into the eye a delivery device that holds an intraocular shunt, and deploying the shunt within the eye. A delivery device holding the shunt enters the eye through a cornea (ab interno approach), and is advanced across the anterior chamber. The delivery device is advanced through the sclera until a distal portion of the device is in proximity to a drainage structure of the eye. The shunt is then deployed from the delivery device, producing a conduit between the anterior chamber and various structures of the eye involved in aqueous humor drainage (e.g., Schlemm's canal, the sclera, or the subconjunctival space). See for example, Yu et al. (U.S. Pat. No. 6,544,249 and U.S. patent application number 2008/0108933) and Prywes (U.S. Pat. No. 6,007,511).
Such a surgical procedure requires an optical apparatus, such as a goniolens, so that a surgeon may visualize the delivery device within the eye and ensure proper placement of the shunt after it has been deployed from the delivery device.